Siemens SINUMERIK 840D sl Function Manual page 169

05.08
Prerequisites
The following prerequisites must be fulfilled for the "safe software cams" function:
S The axis/axes must have been safely referenced (user agreement)
S The safe cams must be configured:
The required cams are enabled using machine data
for 840D sl:
36901: $MA_SAFE_FUNCTION_ENABLE, bits 8...15 and parameter
for SINAMICS S120:
p9501: SI motion, enable safety functions, bits 8...15
SGA assignment is defined using machine data
for 840D sl:
36988: $MA_SAFE_CAM_PLUS_OUTPUT[n] and
36989: $MA_SAFE_CAM_MINUS_OUTPUT[n]
Defining the cam positions
The cam positions are defined in the following machine data/parameters:
for 840D sl:
MD 36936: $MA_SAFE_CAM_POS_PLUS[0...3]
MD 36937: $MA_SAFE_CAM_POS_MINUS[0...3]
for SINAMICS S120:
p9536[n]: SI motion SCA (SN) plus cam position (Control Unit)
p9537[n]: SI motion SCA (SN) minus cam position (Control Unit)
Special case for SN
If the axis is positioned precisely at the parameterized cam position, the cam sig-
nals may have different states owing to system–related variations in the actual val-
ues between the two monitoring channels.
This must be taken into account when safely processing the cam signals, e.g. by
filtering the different signal states by means of a logic circuit (see "Synchronizing
cam signals").
Synchronizing cam signals
As a result of system–related actual value differences, the cam signals of the mon-
itoring channels can have different states. In order to prevent this, the cam syn-
chronization can be activated. This rounds off the results of both channels.
The cam SGAs at the input position of the SPL are synchronized if the user has
parameterized this using the function enable.
Cam signal synchronization is enabled using the following machine data/parame-
ters:
© Siemens AG 2008 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
Safety Functions Integrated in the System/Drive
6.8 Safety software cams and safety cam track (SN)
6-169